Configuring Virtual Link Extension State Tracking

In addition to the above configuration steps, it is often common to also turn on state tracking in order to make sure that link state changes are mirrored:

CLI (network-admin@leaf-1)> vle-create name VLE-1 node-1 leaf-1 node-1-port 10 node-2 leaf-5 node-2-port 17 tracking

This configuration step requires specifying the two vLE nodes (leaf-1 and leaf-5) as well as their respective ports in addition to the tracking option by following this syntax:

The link state tracking configuration can be verified with the vle-show command like so:

CLI (network-admin@leaf-1)> vle-show

name  node-1     node-2     node-1-port node-2-port status tracking

----- ---------- ---------- ----------- ----------- ------ --------

VLE-1 leaf-1     leaf-5     10          17          up     enabled

Furthermore, since a vLE transparently transmits PDUs over to the other end, it is possible to test state tracking by leveraging for example the LLDP protocol messages exchanged between two test switches (sw-1 and sw-2 in the figure above) connected to the vLE ports 10 and 17.

The two test switches exchange LLDP messages by default, so the LLDP peer relationship can just be shown with the command:

CLI (network-admin@sw-1) > lldp-show

switch   local-port chassis-id port-id port-desc         sys-name

-------- ---------- ---------- ------- ----------------- --------

sw-1     1          0b0012c0   1       PN Switch Port(1) sw-2

Then, if a vLE port is disabled (in this case, port 10), the peer relationship is lost and lldp-show does not display a neighbor anymore. The test switch’s port also goes down thanks to vLE state tracking. Once the port is re-enabled, the neighboring relationship is re-established:

CLI (network-admin@leaf-5) > port-config-modify port 17 disable 

CLI (network-admin@sw-1) > port-phy-show port 1

switch   port state speed eth-mode   max-frame learning def-vlan

-------- ---- ----- ----- ---------- --------- -------- --------

sw-1     1    down  10000 10Gbase-cr 1540      off      0        

CLI (network-admin@sw-1) > lldp-show

CLI (network-admin@leaf-5) > port-config-modify port 17 enable

CLI (network-admin@leaf-5) > port-phy-show port 17

port state speed eth-mode max-frame learning def-vlan

---- ----- ----- -------- --------- -------- --------

17   up    10000 10G-SFI  1540      off      0        

CLI (network-admin@sw-1) > port-phy-show port 1

switch   port state speed eth-mode   max-frame learning def-vlan

-------- ---- ----- ----- ---------- --------- -------- --------

sw-1     1    up    10000 10Gbase-cr 1540      off      1        

CLI (network-admin@sw-1) > lldp-show

switch   local-port chassis-id port-id port-desc         sys-name

-------- ---------- ---------- ------- ----------------- --------

sw-1     1          0b0012c0   1       PN Switch Port(1) sw-2

To enable or disable tracking between existing vLE ports, use the vle-modify command:

CLI (network-admin@switch) > vle-modify name name-string tracking|no tracking

To delete a state tracking configuration, use the vle-delete command:

CLI (network-admin@switch) > vle-delete name name-string